The U.S. Navy's system of alpha-numeric ship designators, and its associated hull numbers, have been for several decades a unique method of categorizing ships of all types: combatants, auxiliaries and district craft. Although considerably changed in detail and expanded over the years, this system remains essentially the same as when formally implemented in 1920. It is a very useful tool for organizing and keeping track of naval vessels, and also provides the basis for the identification numbers painted on the bows (and frequently the sterns) of most U.S. Navy ships. The ship designator and hull number system's roots extend back to the late 1880s when ship type serial numbers were assigned to most of the new-construction warships of the emerging "Steel Navy". During the course of the next thirty years, these same numbers were combined with filing codes used by the Navy's clerks to create an informal version of the system that was put in place in 1920. Limited usage of ship numbers goes back even earlier, most notably to the "Jeffersonian Gunboats" of the early 1800s and the "Tinclad" river gunboats of the Civil War Mississippi Squadron. It is important to understand that hull number-letter prefixes are not acronyms, and should not be carelessly treated as abbreviations of ship type classifications. Thus, "DD" does not stand for anything more than "Destroyer". "SS" simply means "Submarine". And "FF" is the post-1975 type code for "Frigate." The hull classification codes for ships in active duty in the United States Navy are governed under Secretary of the Navy Instruction 5030.8D.
Warships Warships are designed to participate in combat operations. The origin of the two-letter code derives from the need to distinguish various cruiser subtypes.
Aircraft carrier type Aircraft carriers are ships designed primarily for the purpose of conducting combat operations by aircraft which engage in attacks against airborne, surface, sub-surface and shore targets. Contrary to popular belief, the "CV" hull classification symbol does not stand for "carrier vessel". "CV" derives from the cruiser designation, with one popular theory that the V comes from French , "to fly", but this has never been definitively proven. The V has long been used by the U.S. Navy for heavier-than-air craft and possibly comes from the French
volplane. Aircraft carriers are designated in two sequences: the first sequence runs from CV-1 USS
Langley to the very latest ships, and the second sequence, "CVE" for escort carriers, ran from CVE-1
Long Island to CVE-127
Okinawa before being discontinued. • AV: Heavier-than-air aircraft tender, later
Seaplane tender (retired) • AVD:
Seaplane tender destroyer (retired) • AVP:
Seaplane tender, Small (retired) • AZ: Lighter-than-air aircraft tender (retired) (1920–1923) • AVG: General-purpose aircraft tender (repurposed
escort carrier) (1941–42) • AVT (i) Auxiliary aircraft transport (retired) • AVT (ii) Auxiliary training carrier (retired) • ACV: Auxiliary aircraft carrier (escort carrier, replaced by CVE) (1942) • CV:
Fleet aircraft carrier (1921–1975), multi-purpose
aircraft carrier (1975–present) • CVA: Aircraft carrier, attack (category merged into CV, 30 June 1975) • CV(N): Aircraft carrier, night (deck equipped with lighting and pilots trained for nighttime fights) (1944) (retired) • CVAN: Aircraft carrier, attack, nuclear-powered (category merged into CVN, 30 June 1975) • CVB: Aircraft carrier, large (original USS
Midway class, category merged into CVA, 1952) • CVE:
Aircraft carrier, escort (retired) (1943–retirement of type) • CVHA: Aircraft carrier, helicopter assault (retired in favor of several LH-series
amphibious assault ship hull codes) • CVHE: Aircraft carrier, helicopter, escort (retired) • CVL:
Light aircraft carrier or aircraft carrier, small (retired) • CVN: Aircraft carrier, nuclear-powered • CVS:
Antisubmarine aircraft carrier (retired) • CVT: Aircraft carrier, training (changed to AVT (auxiliary)) • CVU: Aircraft carrier, utility (retired) • CVG: Aircraft carrier, guided missile (retired) • CF:
Flight deck cruiser (1930s, retired unused) • CVV:
Aircraft carrier, vari-purpose, medium (retired unused)
Surface combatant type Surface combatants are ships which are designed primarily to engage enemy forces on the high seas. The primary surface combatants are battleships, cruisers and destroyers. Battleships are very heavily armed and armored; cruisers moderately so; destroyers and smaller warships, less so. Before 1920, ships were called " no. X", with the type fully pronounced. The types were commonly abbreviated in ship lists to "B-X", "C-X", "D-X" et cetera—for example, before 1920, would have been called "USS
Minnesota, Battleship number 22" orally and "USS
Minnesota, B-22" in writing. After 1920, the ship's name would have been both written and pronounced "USS
Minnesota (BB-22)". In generally decreasing size, the types are: • ACR:
Armored cruiser (pre-1920) • AFSB:
Afloat forward staging base (also AFSB(I) for "interim", changed to MLP (
Mobile Landing Platform, then ESD and ESB) • B: Battleship (pre-1920) • BB:
Battleship • BBG: Battleship, guided missile or
arsenal ship (never used operationally) • BM:
Monitor (1920–retirement) • C:
Cruiser (pre-1920 protected cruisers and peace cruisers) • CA: (first series) Cruiser, armored (retired, comprised all surviving pre-1920 armored and protected cruisers) • CA: (second series)
Heavy cruiser, category later renamed gun cruiser (retired) • CAG:
Cruiser, heavy, guided missile (retired) • CB:
Large cruiser (retired) • CBC: Large command cruiser (never used operationally) • CC: (first usage)
Battlecruiser (never used operationally) • CC: (second usage)
Command cruiser (retired) • CLC: Command cruiser, light (retired) • CG:
Cruiser, guided missile • CGN:
Cruiser, guided missile, nuclear-powered: and • CL:
Cruiser, light (retired) • CLAA:
Cruiser, light, anti-aircraft (retired) • CLD:
Cruiser-destroyer, light (never used operationally) • CLG:
Cruiser, light, guided missile (retired) • CLGN: Cruiser, light, guided missile, nuclear-powered (never used operationally) • CLK:
Cruiser, hunter–killer (never used operationally) • CM:
Cruiser–minelayer (retired) • CS:
Scout cruiser (retired) • CSGN:
Cruiser, strike, guided missile, nuclear-powered (never used operationally) • D: Destroyer (pre-1920) • DD:
Destroyer • DDC: Corvette (briefly proposed in the mid-1950s) • DDE:
Escort destroyer, a destroyer (DD) converted for
antisubmarine warfare – category abolished 1962. (
not to be confused with destroyer escort DE) • DDG:
Destroyer, guided missile • DDK: Hunter–killer destroyer (category merged into DDE, 4 March 1950) • DDR:
Destroyer, radar picket (retired) • DE:
Destroyer escort (World War II, later became
Ocean escort) • DE:
Ocean escort (abolished 30 June 1975) • DEG: Guided missile ocean escort (abolished 30 June 1975) • DER: Destroyer escort, radar picket (abolished 30 June 1975) There were two distinct breeds of DER, the DEs
which were converted to DERs during World War II and
the more numerous postwar DER conversions. • DL: Destroyer leader (later frigate) (retired) • DLG: Destroyer leader, guided missile (later frigate) (abolished 30 June 1975) • DLGN: Destroyer leader, guided missile, nuclear-propulsion (later frigate) (abolished 30 June 1975) The DL category was established in 1951 with the abolition of the CLK category. CLK 1 became DL 1 and DD 927–930 became DL 2–5. By the mid-1950s the term destroyer leader had been dropped in favor of frigate. Most DLGs and DLGNs were reclassified as CGs and CGNs, 30 June 1975. However, DLG 6–15 became DDG 37–46. The old DLs were already gone by that time. Only applied to . • DM: Destroyer, minelayer (retired) • DMS: Destroyer, minesweeper (retired) • FF:
Frigate • PF: Patrol frigate (retired) • FFG: Frigate, guided missile • FFH: Frigate with assigned helicopter • FFL: Frigate, light • FFR: Frigate, radar picket (retired) • FFT: Frigate (reserve training) (retired) The FF, FFG, and FFR designations were established 30 June 1975 as new type symbols for ex-DEs, DEGs, and DERs. The first new-built ships to carry the FF/FFG designation were the s. • PG: Patrol gunboat (retired) • PCH:
Patrol craft, hydrofoil (retired) • PHM:
Patrol, hydrofoil, missile (retired) • K:
Corvette (retired) • LCS:
Littoral combat ship In January 2015, the Navy announced that the up-gunned LCS will be reclassified as a frigate, since the requirements of the
SSC Task Force was to upgrade the ships with frigate-like capabilities. The Navy is hoping to start retrofitting technological upgrades onto existing and under construction LCSs before 2019. • LSES: Large Surface Effect Ship • M:
Monitor (1880s–1920) • SES:
Surface Effect Ship • TB:
Torpedo boat Submarine type Submarines are all self-propelled submersible types (usually started with SS) regardless of whether employed as combatant, auxiliary, or research and development vehicles which have at least a residual combat capability. While some classes, including all diesel-electric submarines, are retired from USN service, non-U.S. navies continue to employ SS, SSA, SSAN, SSB, SSC, SSG, SSM, and SST types. With the advent of new
Air Independent Propulsion/Power (AIP) systems, both SSI and SSP are used to distinguish the types within the USN, but SSP has been declared the preferred term. SSK, retired by the USN, continues to be used colloquially and interchangeably with SS for diesel-electric attack/patrol submarines within the USN, and, more formally, by the Royal Navy and British firms such as
Jane's Information Group. • SC: Cruiser Submarine (retired) • SF: Fleet
Submarine (retired) • SM: Submarine Minelayer (retired) • SS: Submarine,
Attack Submarine • SSA: Submarine Auxiliary, Auxiliary/Cargo Submarine • SSAN: Submarine Auxiliary Nuclear, Auxiliary/Cargo Submarine, Nuclear-powered • SSB: Submarine Ballistic,
Ballistic Missile Submarine • SSBN: Submarine Ballistic Nuclear,
Ballistic Missile Submarine, Nuclear-powered • SSC: Coastal Submarine, over 150 tons • SSG:
Guided Missile Submarine • SSGN: Guided Missile Submarine, Nuclear-powered • SSI: Attack Submarine (Diesel Air-Independent Propulsion) •
SSK:
Hunter-Killer/ASW Submarine (retired) •
SSKN: Hunter-Killer/ASW Submarine, Nuclear-powered (retired) • SSM: Midget Submarine, under 150 tons •
SSN:
Attack Submarine, Nuclear-powered • SSNR: Special Attack Submarine • SSO: Submarine Oiler (retired) • SSP: Attack Submarine (Diesel Air-Independent Power) (alternate use), formerly Submarine Transport • SSQ: Auxiliary Submarine, Communications (retired) • SSQN: Auxiliary Submarine, Communications, Nuclear-powered (retired) • SSR:
Radar Picket Submarine (retired) • SSRN: Radar Picket Submarine, Nuclear-powered (retired) • SST: Training Submarine • SSV:
Submarine Aircraft Carrier (never used) • X:
Midget submarine • IXSS: Unclassified Miscellaneous Submarine • MTS: Moored Training Ship (
Naval Nuclear Power School Training Platform; reconditioned SSBNs and SSNs)
Patrol combatant type Patrol combatants are ships whose mission may extend beyond coastal duties and whose characteristics include adequate endurance and seakeeping, providing a capability for operations exceeding 48 hours on the high seas without support. This notably included
Brown Water Navy/Riverine Forces during the Vietnam War. Few of these ships are in service today. • PBR:
Patrol Boat, River, Brown Water Navy (Pibber or PBR-Vietnam) • PC: Coastal Patrol, originally
Sub Chaser • PCF:
Patrol Craft, Fast; Swift Boat, Brown Water Navy (Vietnam) • PE:
Eagle Boat of
World War I • PF: World War II Frigate, based on British . • PFG: Original designation of • PG: WWII-era
Gunboats, later Patrol combatant, with ability to operate in rivers; what is generally known as
River gunboats • PGH: Patrol Combatant, Hydrofoil () • PHM: Patrol,
Hydrofoil Missile () • PR: Patrol, River, such as the • PT:
Patrol Torpedo Boat, the U.S. take on the
Motor Torpedo Boat (World War II) • PTF:
Patrol Torpedo Fast, Brown Water Navy (Vietnam) • PTG/PTGB: Patrol Torpedo Gunboat •
Monitor: Heavily gunned riverine boat, Brown Water Navy (Vietnam and prior). Named for • ASPB:
Assault Support Patrol Boat, "Alpha Boat", Brown Water Navy; also used as riverine minesweeper (Vietnam) •
PACV:
Patrol Air Cushion Vehicle,
hovercraft that was part of the Brown Water Navy (Vietnam) • SP:
Section Patrol, used indiscriminately for
patrol vessels,
mine warfare vessels, and some other types (World War I; retired 1920)
Amphibious warfare type Amphibious warfare vessels include all ships having an organic capability for amphibious warfare and which have characteristics enabling long duration operations on the high seas. There are two classifications of craft:
amphibious warfare ships, which are built to cross oceans, and
landing craft, which are designed to take troops from ship to shore in an invasion. The U.S. Navy hull classification symbol for a ship with a
well deck depends on its
facilities for aircraft: • An
LSD has a
helicopter deck, which was removable in the older ships. • An
LPD has a hangar in addition to the helicopter deck. • An
LHD or
LHA has a full-length flight deck. Ships • AKA:
Attack Cargo Ship (To LKA, 1969) • APA:
Attack Transport (To LPA, 1969) • APD:
High speed transport (Converted Destroyer or Destroyer Escort) (To LPR, 1969) • APM:
Mechanized Artillery Transports (To LSD) • AGC:
Amphibious Force Flagship (To LCC, 1969) • LCC: (second usage)
Amphibious Command Ship • LHA: General-Purpose Amphibious Assault Ship, also known as
Landing ship, Helicopter, Assault • LHD: Multi-Purpose Amphibious Assault Ship, also known as
Landing ship, Helicopter, Dock • LKA:
Amphibious Cargo Ship (out of commission) • LPA:
Amphibious Transport • LPD:
Amphibious transport dock, also known as Landing ship, Personnel, Dock • LPH:
Landing ship, Personnel, Helicopter • LPR:
High speed transport • LSD:
Landing Ship, Dock • LSH:
Landing Ship, Heavy • LSIL:
Landing Ship, Infantry (Large) (formerly LCIL) • LSL:
Landing Ship, Logistics • LSM:
Landing Ship, Medium • LSM(R): Landing Ship, Medium (Rocket) • LSSL:
Landing Ship, Support (Large) (formerly LCSL) • LST:
Landing Ship, Tank • LST(H):
Landing Ship, Tank (Hospital) • LSV:
Landing Ship, Vehicle Landing Craft • LCA:
Landing Craft, Assault • LCAC:
Landing Craft Air Cushion • LCC: (first usage) Landing Craft, Control • LCFF: (Flotilla Flagship) • LCH: Landing Craft, Heavy • LCI:
Landing Craft, Infantry, World War II-era classification further modified by • (G) – Gunboat • (L) – Large • (M) – Mortar • (R) –
Rocket • LCL:
Landing Craft, Logistics (UK) • LCM:
Landing Craft, Mechanized • LCP: Landing Craft, Personnel • LCP(L):
Landing Craft, Personnel, Large • LCP(R):
Landing Craft, Personnel, Ramped • LCPA: Landing Craft, Personnel, Air-Cushioned • LCS(L):
Landing Craft, Support (Large) changed to
LSSL in 1949 • LCT:
Landing Craft, Tank (World War II era) • LCU:
Landing Craft, Utility • LCVP:
Landing Craft, Vehicle and Personnel • LSH:
Landing Ship Heavy (Royal Australian Navy)
Expeditionary support Operated by Military Sealift Command, have ship prefix "USNS", hull code begins with "T-". • EMS:
Expeditionary Medical Ship, an EPF modified into a hospital ship • EPF:
Expeditionary fast transport • ESB:
Expeditionary Mobile Base (a variant of ESD, formerly Afloat Forward Staging Base (AFSB)) • ESD:
Expeditionary Transfer Dock • HST:
High-Speed Transport (similar to JHSV, not to be confused with WWII-era
High-speed transport (APD)) • HSV: High-Speed Vessel • JHSV: Joint High-Speed Vessel (changed to EPF) • MLP: Mobile Landing Platform (changed to ESD)
Mine warfare type Mine warfare ships are those ships whose primary function is
mine warfare on the high seas. • ADG:
Degaussing ship • AM:
Minesweeper • AMb: Harbor minesweeper • AMc: Coastal minesweeper • AMCU: Underwater mine locater • AMS: Motor minesweeper • CM: Cruiser (i.e., large) minelayer • CMc: Coastal minelayer • DM: High-speed minelayer (converted destroyer) • DMS: High-speed minesweeper (converted-destroyer) • PCS: Submarine chasers (wooden) fitted for minesweeping • YDG: District degaussing vessel In 1955 all mine warfare vessels except for degaussing vessels had their hull codes changed to begin with "M". • MCM:
Mine countermeasures ship • MCS:
Mine countermeasures support ship • MH(C)(I)(O)(S):
Minehunter, (coastal) (inshore) (ocean) (hunter and sweeper, general) • MLC: Coastal minelayer • MSC:
Minesweeper, coastal • MSF: Minesweeper, steel hulled • MSO:
Minesweeper, ocean Coastal defense type Coastal defense ships are those whose primary function is coastal patrol and interdiction. • FS:
Corvette • PB:
Patrol boat • PBR:
Patrol boat, river • PC:
Patrol, coastal • PCE: Patrol craft, escort • PCF: Patrol craft, fast, (swift boat) • PCS: Patrol craft, sweeper (modified-motor minesweepers meant for anti-submarine warfare) • PF:
Frigate, in a role similar to World War II Commonwealth
corvette • PG: Patrol
gunboat • PGM: Motor gunboat (To PG, 1967) • PR: Patrol,
river • SP:
Section patrol Auxiliaries An auxiliary ship is designed to operate in any number of roles supporting combatant ships and other naval operations.
Combat logistics type Ships which have the capability to provide
underway replenishment (UNREP) to fleet units. • AE:
Ammunition ship • AF:
Reefer ship / Stores ship (retired) • AFS:
Combat stores ship • AK:
Dry cargo ship • AKE:
Advanced dry cargo ship • AKS:
General stores ship • AO:
Fleet Oiler • AOE:
Fast combat support ship • AOL:
Light replenishment oiler • AOR:
Replenishment oiler • AVS:
Aviation Stores Issue Ship (retired)
Mobile logistics type Mobile logistics ships have the capability to provide direct material support to other deployed units operating far from home ports. • AC:
Collier (retired) • AD:
Destroyer tender • AGP:
Patrol craft tender • AR:
Repair ship • ARB:
Repair ship, battle damage • ARC:
Repair ship, cable • ARG:
Repair ship, internal combustion engine • ARH: Repair ship, heavy-hull • ARL:
Repair ship, landing craft • ARV: Repair ship, aircraft • ARVH: Repair ship, aircraft, helicopter • AS:
Submarine tender • AW:
Distilling ship (retired)
Support ships Support ships are not designed to participate in combat and are generally not armed. For ships with civilian crews (owned by and/or operated for
Military Sealift Command and the
Maritime Administration), the prefix T- is placed at the front of the hull classification. Support ships are designed to operate in the open ocean in a variety of sea states to provide general support to either combatant forces or shore-based establishments. They include smaller auxiliaries which, by the nature of their duties, leave inshore waters. • AB: Auxiliary Crane Ship (1920–41) • ACS:
Auxiliary Crane Ship • AG:
Miscellaneous Auxiliary • AGB:
Icebreaker • AGDE: Testing Ocean Escort • AGDS:
Deep Submergence Support Ship • AGEH: Hydrofoil, experimental • AGER: (i): Miscellaneous Auxiliary, Electronic Reconnaissance • AGER: (ii):
Environmental Research Ship • AGF:
Miscellaneous Command Ship • AGFF: Testing Frigate • AGHS: Patrol combatant support ship—ocean or inshore • AGL: Auxiliary vessel,
lighthouse tender • AGM:
Missile Range Instrumentation Ship • AGMR:
Major Communications Relay Ship • AGOR:
Oceanographic Research Ship • AGOS:
Ocean Surveillance Ship • AGR:
Radar picket ship • AGS:
Surveying Ship • AGSC:
Coastal Survey Ships • AGSE: Submarine and Special Warfare Support • AGTR:
Technical research ship • AH:
Hospital ship • AKD: Cargo Ship, Dock • AKL:
Cargo Ship, Small • AKN:
Cargo Ship, Net • AKR:
Cargo Ship, Vehicle • AKV:
Cargo Ship, Aircraft • AN:
Net laying ship • AOG:
Gasoline tanker • AOT:
Transport Oiler • AP:
Transport • APB:
Self-propelled Barracks Ship • APC:
Coastal Transport • APc:
Coastal Transport, Small • APH:
Evacuation Transport • APL:
Barracks Craft • ARS:
Rescue and Salvage Ship • ARSD:
Salvage Lifting Vessels • ASR:
Submarine Rescue Ship • AT:
Fleet Tug • ATA:
Auxiliary Ocean Tug • ATF:
Fleet Ocean Tug • ATLS: Drone Launch Ship • ATO:
Fleet Tug, Old • ATR:
Rescue Tug • ATS:
Salvage and Rescue Ship • AVB(i): Aviation Logistics Support Ship • AVB(ii): Advance Aviation Base Ship • AVM: Guided Missile Ship • AVT(i): Auxiliary Aircraft Transport • AVT(ii): Auxiliary Aircraft Landing Training Ship • EPCER: Experimental – Patrol Craft Escort – Rescue • PCER: Patrol Craft Escort – Rescue • SBX:
Sea-based X-band Radar – a mobile
active electronically scanned array early-warning radar station.
Service type craft Service craft are navy-subordinated craft (including non-self-propelled) designed to provide general support to either combatant forces or shore-based establishments. The suffix "N" refers to non-self-propelled variants. • AFDB:
Large Auxiliary Floating
Dry Dock • AFD/AFDL:
Small Auxiliary Floating Dry Dock • AFDM:
Medium Auxiliary Floating Dry Dock • ARD:
Auxiliary Repair Dry Dock • ARDM:
Medium Auxiliary Repair Dry Dock • JUB/JB: Jack Up Barge
Submersibles • DSRV:
Deep Submergence Rescue Vehicle • DSV:
Deep Submergence Vehicle • NR: Submersible Research Vehicle
Yard and district craft • YAG: Miscellaneous Auxiliary Service • YC:
Open Lighter • YCF:
Car Float • YCV: Aircraft Transportation Lighter • YD: Floating
Crane • YDT: Diving Tender • YF:
Covered Lighter • YFB:
Ferry Boat or Launch • YFD:
Yard Floating Dry Dock • YFN: Covered Lighter (non-self propelled) • YFNB: Large Covered Lighter (non-self propelled) • YFND: Dry Dock Companion Craft (non-self propelled) • YFNX: Lighter (Special purpose) (non-self propelled) • YFP:
Floating Power Barge • YFR:
Refrigerated Cover Lighter • YFRN:
Refrigerated Covered Lighter (non-self propelled) • YFRT:
Range Tender USNS Range Recoverer (T-AG-161) • YFU: Harbor Utility Craft • YG:
Garbage Lighter • YGN:
Garbage Lighter (non-self propelled) • YH:
Ambulance boat/small medical support vessel • YLC: Salvage Lift Craft • YM:
Dredge • YMN:
Dredge (non-self propelled) • YNG:
Net Gate Craft • YN:
Yard Net Tender • YNT:
Net Tender • YO:
Fuel Oil Barge • YOG:
Gasoline Barge • YOGN:
Gasoline Barge (non-self propelled) • YON:
Fuel Oil Barge (non-self propelled) • YOS:
Oil Storage Barge • YP:
Patrol Craft, Training • YPD: Floating Pile Driver • YR: Floating Workshop • YRB:
Repair and Berthing Barge • YRBM: Repair, Berthing and Messing Barge • YRDH: Floating Dry Dock Workshop (Hull) • YRDM: Floating Dry Dock Workshop (Machine) • YRR:
Radiological Repair Barge nuclear ships and submarines service • YRST:
Salvage Craft Tender • YSD:
Seaplane Wrecking Derrick – Yard Seaplane Derrick • YSR: Sludge Removal Barge • YT:
Harbor Tug (craft later assigned YTB, YTL, or YTM classifications) • YTB:
Large Harbor tug • YTL:
Small Harbor Tug • YTM:
Medium Harbor Tug • YTT:
Torpedo trials craft • YW:
Water Barge • YWN:
Water Barge (non-self propelled)
Miscellaneous ships and craft • ID or Id. No.:
Civilian ship taken into service for auxiliary duties, used indiscriminately for large ocean-going ships of all kinds and coastal and yard craft (World War I; retired 1920) • IX:
Unclassified Miscellaneous Unit • "none": To honor her unique historical status,
USS Constitution, formerly IX 21, was reclassified to "none", effective 1 September 1975.
Airships Although aircraft, pre-World War II rigid airships were commissioned (no different from surface warships and submarines), flew the U.S. ensign from their stern and carried a United States Ship (USS) designation. Rigid airships: • ZR:
Rigid airship • ZRS: Rigid airship scout •
ZRCV: Rigid airship aircraft carrier, proposed, not built Lighter-than-air aircraft (e.g.,
blimps) continued to fly the U.S. ensign from their stern but were registered as aircraft:
Temporary designations United States Navy Designations (Temporary) are a form of U.S. Navy ship designation, intended for temporary identification use. Such designations usually occur during periods of sudden mobilization, such as that which occurred prior to, and during,
World War II or the
Korean War, when it was determined that a sudden temporary need arose for a ship for which there was no official Navy designation. During
World War II, for example, a number of commercial vessels were requisitioned, or acquired, by the U.S. Navy to meet the sudden requirements of war. A
yacht acquired by the U.S. Navy during the start of World War II might seem desirable to the Navy whose use for the vessel might not be fully developed or explored at the time of acquisition. On the other hand, a U.S. Navy vessel, such as the yacht in the example above, already in commission or service, might be desired, or found useful, for another need or purpose for which there is no official designation. • IX: Unclassified Miscellaneous Auxiliary Ship, for example, yacht
Chanco acquired by the U.S. Navy on 1 October 1940. It was classified as a
minesweeper , but instead, mainly used as a
patrol craft along the
New England coast. When another assignment came, and it could not be determined how to classify the vessel, it was redesignated IX-175 on 10 July 1944. • IXSS: Unclassified Miscellaneous Submarines, such as the , the and the . • YAG: Miscellaneous Auxiliary Service Craft, such as the , and which, curiously, was earlier known as . Numerous other U.S. Navy vessels were launched with a temporary, or nominal, designation, such as YMS or PC, since it could not be determined, at the time of construction, what they should be used for. Many of these were vessels in the 150 to 200 feet length class with powerful engines, whose function could be that of a
minesweeper,
patrol craft,
submarine chaser,
seaplane tender,
tugboat, or other. Once their destiny, or capability, was found or determined, such vessels were reclassified with their actual designation. == United States Coast Guard vessels ==